I. Field of the Invention
This invention relates a method of manufacturing plastic components wherein the plastic overlay coat is mechanically locked over a thermoplastic polymer resin base material and, in particular, to a method of applying a plastic fascia through a low-pressure injection molding process to a polystyrene base which has been molded to the desired configuration of the component.
II. Description of the Prior Art
With the increased emphasis on the reduction of vehicle weight for improved performance and fuel savings more vehicle components are being manufactured of lightweight plastics. Additionally, the properties of plastics lends itself in molding ornamental and performance components of motor vehicles. Examples of components which have in the past been molded from plastics include wheel covers, vehicle dams and spoilers, dashboards, etc. However, the pliable nature of thin plastic components requires that a support intrastructure be provided usually by adding metal support structure. Although the ornamental properties of the plastic component are retained, the weight and cost reduction advantages are negated.
In addition to providing the desired ornamental effect, plastic vehicle components must withstand the rigors of the road. Vehicle wheel covers must remain attached to the metal rim even under the stresses produced by the road surface. Additionally, such wheel covers should reduce road noise while withstanding the heat generated by modern disc brakes. Plastic air dams and spoilers must be flexible enough to withstand the forces associated with the moving vehicle yet strong enough to withstand damage. Yet throughout the vehicles life components must maintain their ornamental and aesthetic features.